Can You Really Out-Exercise a Bad Diet?
By: Brian Hoeflinger, MD
August 31, 2025 | #60
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Disclaimer: Opinions are my own. Not medical advice.
Medical Trivia of the Week
How many calories are in one pound of body fat? (the correct answer is at the end of this email)
- A) 3,500 calories
- B) 2,000 calories
- C) 2,500 calories
- D) 4,500 calories
Is It Better to Eat Less or Exercise More?
We all want to know: should we eat less or exercise more? The truth is, both matter, but not in the way most people think. Let me explain with a personal example.
Yesterday, I went rucking, walking with weight on your back. I covered 6 miles with 25 pounds at a 16-minute pace, finishing in 1 hour and 37 minutes. My Garmin watch recorded 430 active calories burned.
Later that day, my son-in-law brought home a dozen Dunkin’ Donuts. I couldn’t resist and ate one crème-filled donut. Out of curiosity, I checked the calorie count:
- Crème-filled donut = 300 calories
- Glazed donut = 250 calories
So in just two minutes of eating, I consumed 300 of the 430 calories I had worked so hard to burn. If I’d added a glazed donut, that would’ve been 550 calories, completely wiping out my workout. And if I’d topped it off with a caramel swirl coffee with cream (another 340 calories), I would’ve gone well past what I burned, with very little nutritional value to show for it.
The point isn’t to pick on donuts. It’s to show how easy it is to consume calories and how much harder it is to burn them off through exercise.
Why Exercise Still Matters
You might think this means exercise doesn’t matter. But that’s not true. The benefits of physical activity go far beyond calorie burn:
- Cardiovascular health: lowers blood pressure, cholesterol, and risk of heart disease.
- Metabolic health: regulates blood sugar and lowers the risk of type 2 diabetes.
- Bone and muscle strength: slows osteoporosis, builds strength, and improves balance.
- Mental health: reduces stress, anxiety, and depression while boosting mood.
- Brain health: improves memory and may protect against dementia.
- Immune function and energy: helps you fight off illness and feel more energized.
Exercise is medicine for your body and mind. But when it comes to managing your weight, it’s not the full answer.
Why Diet Is the Deciding Factor
Think about it: a bagel is about 300 calories, but doesn’t keep you full for long. Compare that with one egg, a banana, and an apple (together under 300 calories), with far more nutrients and satiety. Or a protein shake with fruit for the same calorie cost, which fuels your body much better than the bagel.
It’s not just about calories, it’s about nutritional value. Two foods may contain the same calories, but one will nourish and satisfy you, while the other leaves you hungrier and reaching for more.
That’s why studies show that a majority of weight loss comes from diet choices, while exercise is key for keeping the weight off and improving long-term health.
The Bottom Line
At the end of the day, you have to find what works for your lifestyle. Whether your goal is weight loss, better health, or both, the key is a balance of diet and exercise. When you put a combine a healthy diet with consistent exercise, you give yourself the best chance at living a stronger, longer, and healthier life.
And here’s the hard truth: it’s far easier to eat 500 calories than it is to burn them off. I spent over 90 minutes rucking to burn 430 calories, and erased most of that effort with a single donut.
The good news? You don’t have to be perfect. Small improvements in your food choices and steady, consistent activity add up over time to huge changes in your health.
So what’s one small change you can make this week, whether in your diet or activity, that will have the biggest impact? Start tomorrow and track your results. You might be surprised how much of a difference it makes.
Impactful Quote of the Week
"The food you eat can be the safest and most powerful form of medicine, or the slowest form of poison."
- Ann Wigmore
All my best,
Brian Hoeflinger
P.S. - if you enjoyed this newsletter, you may enjoy my book that details my life as neurosurgeon and the loss of my oldest son, Brian (see below a synopsis).
Check out My Podcast
The Hoeflinger Podcast is about more than medicine, it’s about living a fuller, healthier, and more meaningful life. Together with my son, Kevin, we discuss medicine, health, fitness, lessons learned from personal tragedy, family, and purpose. Along the way, we invite inspiring guests to bring fresh insights and perspectives. Watch or listen to the podcast below.
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Check out My Book
Life and Death . . . Two words with such opposite meaning and which inflict such contradictory emotions and yet are so closely intertwined in our lives. As parents, we bring meaning and life into this world through our children. Our lives become defined as a result. We learn the joy, hardship, and responsibility of shaping an innocent life. But a day will come when that life will be taken. For some, death will come too soon. This is the story of my son, Brian Nicholas Hoeflinger, who died unexpectedly at age 18.
https://doctorhoeflinger.com/products/the-night-he-died-the-harsh-reality-of-teenage-drinking
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Medical Trivia Answer:
The correct answer is A) 3,500 calories
*Disclaimer: This newsletter and blog is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional health care services, including the giving of medical advice, and no doctor/patient relationship is formed. The use of information on this newsletter and blog or materials linked from this newsletter and blog is at the user’s own risk. The content of this newsletter and blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard or delay seeking medical advice for any medical condition they may have and should consult their healthcare professionals for any such conditions.
